1. Field of the Invention
This invention relates to a process for preparing electrically conductive poly(isothianaphthene) from 1,3-dihydroisothianaphthene. More particularly, this invention relates to such a process in which poly(isothianaphthene) is prepared by chemical means.
2. Prior Art
The field of polymeric conductors is rapidly expanding as more and more uses for these materials are being developed. Poly(heterocycles) have received attention because they can be prepared in film form, and because as a class, they are often more stable to atmospheric exposure than poly(acetylene) and doped poly(phenylene).
Electrically conductive poly(isothianaphthene) is potentially a useful polymeric conductor. One of the disadvantages attendant to the use of this material is the difficulty associated with its preparation. The conventional route for preparing electrically conductive poly(isothianaphthene) is described in F. Wudl, M. Kobayaski and A. J. Heeger, "Poly(isothianaphthene)", J. Org. Chem., 49, pp. 3382-3384 (1984). In this procedure, 1,3-dihydroisothianaphthene is converted into dihydroisothianaphthene S-oxide by the oxidation with sodium periodate in aqueous methanol. Dihydroisothianaphthene s-oxide is then dehydrated by treatment with a dehydration agent, such as Al.sub.2 O.sub.3, at elevated temperature to form isothianaphthene which is, in turn, polymerized electrochemically in anhydrous solvents to form the electrically conductive poly(isothianaphthene) which is doped with the anion of the cell electrolyte.